This invention relates to an oil return system for an overhead cam engine and more particularly to an improved and highly effective system for returning oil from the valve operating mechanism to the crankcase.
The advantages of overhead valves for internal combustion engines are well known. The advantages of the overhead valve placement can be maximized by operating the valves directly from overhead mounted camshafts. Although such arrangements provide good performance, it is, of course, necessary to provide adequate lubrication for the valve actuating components. In additional to providing good lubrication for these components, it is also necessary to insure drainage of the lubricant back to the crankcase of the engine. The cylinder head in which the valves are positioned is, however, separated from the crankcase by the cylinder block and this presents certain difficulties with oil return. In addition, the valve mechanism is frequently located in an inclined manner both transversely and longitudinally. That is, with a V-type or inclined engine, one of the cam chambers may be inclined transversely to the horizontal. Also, it is the normal practice to mount an engine with its crankshaft somewhat offset from the horizontal and this also can present oil return problems in connection with the lubricating system of the valve actuators. Furthermore, when overhead camshafts are employed, it is the practice to support the camshaft for rotation at a number of places along its length so as to prevent flucture of the camshaft. The bearings themselves at as oil return dams thus further complicating the oil return arrangement.
It is, therefore, a principal object of this invention to provide an improved and simplified oil return arrangement an overhead valve internal combustion engine.
It is a still further object of this invention to provide an improved oil return system for the valve lubricating mechanism of an engine in which the valve actuating mechanism is inclined.
It is yet further object of this invention to provide an improved and simplified oil return system for an internal combustion engine and its valve actuating mechanism that will insure good drainage of the oil and return to the crankcase under all running conditions.